rynostang46

So I know I am gonna get some flack for this but...I bought my 4x4 Screw a few months ago. I found the exact color I wanted with all the extras I was looking for. I did look at the window sticker to see 3.55 rear end, which was fine with me...however, I was cleaning out my truck and looking over my window stick and it hit me.. I have an open differential! What the heck. $35000+ on a truck and the 4x4 has an open rear end differential. Can anyone explain to me (or school me) on why they would put that on a 4wd. If you build it on Ford's website and click the 3.55 rear end with non lsd it actually upcharges straight to the 4x4 truck!

Thanks and dont be to hard on me.

Viking1204

What do mean by "open" differential?

rynostang46

Non lsd. One wheel spinning on a boat ramp type stuff.

Viking1204

Had me worried but I guess I'm ok. My Sticker says I have the 3.73 Electronic Lock RR Axle. Time to do some more research online.

SultanGris

what year? What trim level? the 2011 and newer with open difs can have a locker if its fx4 or lariat, not sure which other trims have it, and they also have whats called electronic wheel slip which hits the brakes and makes it act like a LSD. Personally Id rather have the LSD any day than either of those because its much more functional and practical than a locker unless you are actually doing some serious off roading and hanging tires in the air, which no one is with a 40-50K super crew f150, so why they even put lockers in these trucks is beyond me. If I was out doing that I would have a jeep for sure.

mrpositraction

I have an FX4 with the 3.73 electronic locking rearend which means it is an open differential. I backed into the sand at the beach . When I went to leave one tire spun, I let out got back in it and both tires dug down at the same rate. The electronics do a lot to help these rearends behave better as an open differential.

In fact I have rarely had one tire spin with this 2011. My 2010 FX4 was scary with its open so they came along way in a year.

mrpositraction

Here is the situation i was in. 2wd I would have been screwed!

SultanGris

yea, thats the electronic wheel spin control, unless you locked it in manually. The 2010s and prior didnt have it, those fx4s with lockers are a pain in the *** to drive because you always have to lock it in or you arent going anywhere, and then it unlocks at like 25 MPH or something. The 2011 and newer work way better for sure! My buddy has a 2010 fx4 locker and hates it, wishes he wouldve got a LSD instead, lol! He checks oil wells down lease roads which are frequently muddy so its a huge inconvenience having to stop and lock it in 4 and locker every time where a 2wd LSD truck can just drive right through the mud unless its really bad, but the open dif without the electronic wheel spin has no chance, lol!

8uzzsaw

4x4 with LSD all the way!

rynostang46

I have an XLT screw 5.0 with 3.55 non lsd. I am going to have to look into adding a LSD later